This invention relates to a negative type disc brake which constantly performs a braking operation by pressing friction pads against a rotor by means of an actuating spring disposed inside a cylinder and which is released from the braking operation when a fluid pressure is applied causing it to disengage the friction pads from the rotor.
Generally, in a negative disc brake of the type as described in the foregoing, the thrusting force which presses the friction pads against the rotor derives from an actuating spring disposed in a cylinder. Therefore, where such thrusting force is required in different degrees to ensure satisfactory braking for varied types of equipments, each negative disc brake must be equipped with an actuating spring of a characteristic that suits for a specific equipment. Furthermore, there have been contrived various devices for the automatic adjustment of gaps between thrusting cylinders and rotors according as friction pads wear away in such negative disc brakes.
However, the variation required among negative disc brakes for the above stated reason relates only to the shape and arrangement of a thrusting piston, an actuating spring and an adjustment screw which are contained in a cylinder assembly and not relates to a caliper assembly which is provided with friction pads and arranged to straddle a rotor. The structure of the caliper assembly does not have to vary with the specific negative disc brake employed.